Скачать или смотреть Generating a List of Lists from CSV Files in Python

Learn how to extract content from multiple CSV files stored in a folder and organize it into a `list of lists` using Python. Step-by-step guide included.
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Generating a List of Lists from CSV Files in Python

Are you looking to process multiple CSV files stored in a single folder and want to extract their content into a more manageable structure in Python? You’ve come to the right place! This post will show you how to create a list of lists where each inner list contains the lines of a corresponding CSV file.

Understanding the Problem

When working with a folder full of CSV files, you might want to collect all the data contained within them for further analysis. However, you discovered that your initial approach was not providing the intended output.

Instead of achieving a list of lists, your current method combined all the data into a single, large list. This is a common hurdle for beginners, but fear not—there’s a simple logical fix!

The Solution Explained

Let’s break down the solution into easy-to-follow steps:

Step 1: Import Required Libraries

First, make sure to import the listdir function from the os module. This will help you list all the files in your specified folder.

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Step 2: Set Up Your Folder Path

You need to specify the path of your folder which contains the CSV files.

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Step 3: Get the List of Filenames

With the folder path set, you can now retrieve the names of all the files in that folder using listdir().

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Create a Container for Your Data

Before you start processing the files, you need to initialize an empty list. This list will hold the content of each file as a separate list.

[[See Video to Reveal this Text or Code Snippet]]

Step 5: Loop Through the Files

Now it’s time to loop through each file in the folder. For each file, you will:

Create the path to the file.

Open the file using a context manager (this ensures that files are properly closed afterward).

Read the lines of the file.

Append the lines to your main list.

Here’s how this looks in code:

[[See Video to Reveal this Text or Code Snippet]]

Step 6: Output the Result

Finally, you can print out files_content to see the structure you’ve created—each inner list corresponds to the lines of a specific CSV file.

[[See Video to Reveal this Text or Code Snippet]]

Complete Code Example

Here’s what the complete code looks like:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By following the above steps, you can effectively read multiple CSV files from a folder and store their contents in a structured manner—specifically, a list of lists. This format is much easier to work with, especially for data analysis tasks.

Hopefully, this helps you move forward in your programming journey! Happy coding!